/*
 *                  Egothor Software License version 1.00
 *                  Copyright (C) 1997-2004 Leo Galambos.
 *               Copyright (C) 2002-2004 "Egothor developers"
 *                    on behalf of the Egothor Project.
 *                           All rights reserved.
 *
 * This  software  is  copyrighted  by  the "Egothor developers". If this
 * license applies to a single file or document, the "Egothor developers"
 * are the people or entities mentioned as copyright holders in that file
 * or  document.  If  this  license  applies  to the Egothor project as a
 * whole,  the  copyright holders are the people or entities mentioned in
 * the  file CREDITS. This file can be found in the same location as this
 * license in the distribution.
 *
 * Redistribution  and  use  in  source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 * 1. Redistributions  of  source  code  must retain the above copyright
 *    notice, the list of contributors, this list of conditions, and the
 *    following disclaimer.
 * 2. Redistributions  in binary form must reproduce the above copyright
 *    notice, the list of contributors, this list of conditions, and the
 *    disclaimer  that  follows  these  conditions  in the documentation
 *    and/or other materials provided with the distribution.
 * 3. The name "Egothor" must not be used to endorse or promote products
 *    derived  from  this software without prior written permission. For
 *    written permission, please contact Leo.G@seznam.cz
 * 4. Products  derived  from this software may not be called "Egothor",
 *    nor  may  "Egothor"  appear  in  their name, without prior written
 *    permission from Leo.G@seznam.cz.
 *
 * In addition, we request that you include in the end-user documentation
 * provided  with  the  redistribution  and/or  in the software itself an
 * acknowledgement equivalent to the following:
 * "This product includes software developed by the Egothor Project.
 *  http://egothor.sf.net/"
 *
 * THIS  SOFTWARE  IS  PROVIDED  ``AS  IS''  AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES,  INCLUDING,  BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY  AND  FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN  NO  EVENT  SHALL THE EGOTHOR PROJECT OR ITS CONTRIBUTORS BE LIABLE
 * FOR   ANY   DIRECT,   INDIRECT,  INCIDENTAL,  SPECIAL,  EXEMPLARY,  OR
 * CONSEQUENTIAL  DAMAGES  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE  GOODS  OR  SERVICES;  LOSS  OF  USE,  DATA, OR PROFITS; OR
 * BUSINESS  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER  IN  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This  software  consists  of  voluntary  contributions  made  by  many
 * individuals  on  behalf  of  the  Egothor  Project  and was originally
 * created by Leo Galambos (Leo.G@seznam.cz).
 */
package org.egothor.stemmer;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import org.apache.lucene.internal.hppc.ObjectCursor;

/**
 * The Gener object helps in the discarding of nodes which break the reduction effort and defend the
 * structure against large reductions.
 */
public class Gener extends Reduce {
  /** Constructor for the Gener object. */
  public Gener() {}

  /**
   * Return a Trie with infrequent values occurring in the given Trie removed.
   *
   * @param orig the Trie to optimize
   * @return a new optimized Trie
   */
  @Override
  public Trie optimize(Trie orig) {
    List<CharSequence> cmds = orig.cmds;
    List<Row> rows = new ArrayList<>();
    List<Row> orows = orig.rows;
    int[] remap = new int[orows.size()];

    Arrays.fill(remap, 1);
    for (int j = orows.size() - 1; j >= 0; j--) {
      if (eat(orows.get(j), remap)) {
        remap[j] = 0;
      }
    }

    Arrays.fill(remap, -1);
    rows = removeGaps(orig.root, orows, new ArrayList<>(), remap);

    return new Trie(orig.forward, remap[orig.root], cmds, rows);
  }

  /**
   * Test whether the given Row of Cells in a Trie should be included in an optimized Trie.
   *
   * @param in the Row to test
   * @param remap Description of the Parameter
   * @return <code>true</code> if the Row should remain, <code>false
   *      </code> otherwise
   */
  public boolean eat(Row in, int[] remap) {
    int sum = 0;
    for (Iterator<ObjectCursor<Cell>> i = in.cells.values().iterator(); i.hasNext(); ) {
      Cell c = i.next().value;
      sum += c.cnt;
      if (c.ref >= 0) {
        if (remap[c.ref] == 0) {
          c.ref = -1;
        }
      }
    }
    int frame = sum / 10;
    boolean live = false;
    for (Iterator<ObjectCursor<Cell>> i = in.cells.values().iterator(); i.hasNext(); ) {
      Cell c = i.next().value;
      if (c.cnt < frame && c.cmd >= 0) {
        c.cnt = 0;
        c.cmd = -1;
      }
      if (c.cmd >= 0 || c.ref >= 0) {
        live |= true;
      }
    }
    return !live;
  }
}
